1. Field of the Invention
The present invention relates to a print control method and a printing system in a system connecting an information apparatus such as a computer and a printer by wireless communication using electromagnetic wave or light as a medium. The present invention relates more particularly to a print control method and a printing system in which a printer preliminary notifies a period of time it takes before it becomes ready to receive print data.
2. Description of the Background Art
A conventional output unit such as a printer is connected to an information apparatus such as a computer by a signal cable. However, the laying of the signal cable is in some cases difficult. In such case, if the connection is made by radiocommunication, the output unit and the information apparatus can be provided remote from each other, or one printer can be shared by a plurality of computers. In addition, a portable apparatus including an electronic organizer, a portable information terminal or a digital camera is in most cases not connected to a network. Radiocommunication allows such portable apparatus to transfer data to a printer without any cable connection.
The portable apparatus is required to reduce its power consumption. When the network connection is achieved by radiocommunication, communication time must extremely be reduced. When the portable apparatus uses a printer, the portable apparatus must inquire if the printer is presently ready to use. The radiocommunication required for the inquiry must be reduced to save electric power.
In a usual printer, data to be output is temporarily stored for subsequent processing. However, in a printer processing data with a large amount of information such as a color printer, generally, data corresponding to one page is received at a time and next data cannot be received until printout of the data is completed. When a plurality of pages are sequentially output from such printer, the portable apparatus must detect completion of the processing of the currently processed page and then transfer data corresponding to a next page. In addition, when the printer is in the process of printout by a request from another apparatus, the portable apparatus must detect completion of the processing and again give the printer a request for printout.
The following method is widely used to solve this problem. More specifically, a printer which has received a request for printout from an information apparatus notifies the information apparatus of completion of printout processing when the printout processing for another apparatus is completed. Further, when the printer receives a request for printout in the process of printout, the printer registers an identifier indicating that information apparatus which gave the request in a queue. When a current printout is completed, the printer notifies the information apparatus which is registered in the first place of the queue that printout is possible. At the same time, the printer eliminates the identifier of the notified information apparatus from the queue. By using this method, the printer can successively print out a plurality of pages. In addition, the printer can automatically process requests for printout transmitted from a plurality of information apparatuses sequentially.
In a system disclosed in Japanese Patent Laying-Open No. 9-93672, when radiocommunication is possible between an information apparatus and a printer, the information apparatus inquires the printer at regular intervals. In addition, the information apparatus always diplays a status of the printer on its screen in the form of icon. Thus, information on the current status of the printer and completion of printout processing is available to a user.
In the former method, however, the information apparatus must always be maintained in a status of a radiocommunication until printout is completed. Electric power is consumed therefor, thereby preventing reduction in electric power. Further, when the information apparatus fails to receive a signal indicating completion of the processing from the printer for transient accident, the information apparatus would continue to wait for the signal indicating the completion of the processing in a status of reception.
In the latter method, although the information apparatus transmits data at regular intervals, generally, much larger amount of electric power is consumed at the time of transmission than reception. Thus, reduction in interval for inquiry increases electric power consumption. On the other hand, if the interval for inquiry is increased, a period of time from completion of printout processing to next inquiry is also increased. This results in another problem of wasting time. Therefore, in a conventional method, for successive printout, the information apparatus must maintain the status of reception or frequently inquire the printer. Thus, power consumption on the side of the information apparatus cannot be reduced. On the other hand, if the power consumption on the side of the information apparatus is to be reduced, the information apparatus must increase the interval for inquiry with respect to the printer, making it difficult to successively print out from the printer. Therefore, it is difficult to solve both problems at the same time.